Space-filling intragastric implants with fluid flow

ABSTRACT

A variety of passive intragastric implant devices for obesity treatment are disclosed. Such passive devices do not autonomously change shape, but instead react within the stomach to induce satiety. The devices may take up volume within the stomach, thus reducing the intake capacity. Additionally, the devices may contact areas within the stomach, such as the cardia surrounding the esophageal sphincter, to stimulate satiety-inducing nerves. Also, certain devices slow gastric emptying by blocking or otherwise impeding flow through the pyloric sphincter. A number of devices combine two or more of these satiety-inducing features. Methods of implant are disclosed including compressing the devices within a delivery tube and transorally advancing the devices through the esophagus to be deployed within the stomach. Removal of the devices occurs in the reverse.

RELATED APPLICATIONS

The present application is a divisional of U.S. Ser. No. 13/275,211,filed Oct. 17, 2011, which claims priority under 35 U.S.C. § 119 to U.S.Provisional Application No. 61/485,009, filed May 11, 2011, and to61/394,592, filed Oct. 19, 2010, the disclosures of all of which areincorporated by reference herein.

FIELD OF THE INVENTION

The present invention is directed to intragastric implants used for thetreatment of obesity, and in particular to implants and systems forplacement in the stomach cavity that take up space and providealternative flow paths.

BACKGROUND OF THE INVENTION

Over the last 50 years, obesity has been increasing at an alarming rateand is now recognized by leading government health authorities, such asthe Centers for Disease Control (CDC) and National Institutes of Health(NIH), as a disease. In the United States alone, obesity affects morethan 60 million individuals and is considered the second leading causeof preventable death. Worldwide, approximately 1.6 billion adults areoverweight, and it is estimated that obesity affects at least 400million adults.

Obesity is caused by a wide range of factors including genetics,metabolic disorders, physical and psychological issues, lifestyle, andpoor nutrition. Millions of obese and overweight individuals first turnto diet, fitness and medication to lose weight; however, these effortsalone are often not enough to keep weight at a level that is optimal forgood health. Surgery is another increasingly viable alternative forthose with a Body Mass Index (BMI) of greater than 40. In fact, thenumber of bariatric surgeries in the United States was estimated to beabout 400,000 in 2010.

Examples of surgical methods and devices used to treat obesity includethe LAP-BAND® (Allergan Medical of Irvine, Calif.) gastric band and theLAP-BAND AP® (Allergan). However, surgery might not be an option forevery obese individual; for certain patients, non-surgical therapies orminimal-surgery options are more effective or appropriate.

In the early 1980s, physicians began to experiment with the placement ofintragastric balloons to reduce the size of the stomach reservoir, andconsequently its capacity for food. Once deployed in the stomach, theballoon helps to trigger a sensation of fullness and a decreased feelingof hunger. These devices are designed to provide therapy for moderatelyobese individuals who need to shed pounds in preparation for surgery, oras part of a dietary or behavioral modification program. These balloonsare typically cylindrical or pear-shaped, generally range in size from200-500 ml or more, are made of an elastomer such as silicone,polyurethane, or latex, and are filled with air, an inert gas, water, orsaline.

One such inflatable intragastric balloon is described in U.S. Pat. No.5,084,061 and is commercially available as the BioEnterics IntragastricBalloon System (“BIB System,” sold under the trademark ORBERA). The BIBSystem comprises a silicone elastomer intragastric balloon that isinserted into the stomach and filled with fluid. Conventionally, theballoons are placed in the stomach in an empty or deflated state andthereafter filled (fully or partially) with a suitable fluid. Theballoon occupies space in the stomach, thereby leaving less roomavailable for food and creating a feeling of satiety for the patient.Placement of the intragastric balloon is non-surgical, trans-oral,usually requiring no more than 20-30 minutes. The procedure is performedgastroscopically in an outpatient setting, typically using localanesthesia and sedation. Placement of such balloons is temporary, andsuch balloons are typically removed after about six months. Removing theballoon requires deflation by puncturing with a gastroscopic instrument,and either aspirating the contents of the balloon and removing it, orallowing the fluid to pass into the patient's stomach. Clinical resultswith these devices show that for many obese patients, the intragastricballoons significantly help to control appetite and accomplish weightloss.

Some attempted solutions for weight loss by placing devices in thestomach result in unintended consequences. For instance, some devicestend to cause food and liquid to back up in the stomach, leading tosymptoms of gastroesophageal reflux disease (GERD), a condition in whichthe stomach contents (food or liquid) leak backwards from the stomachinto the esophagus. Also, the stomach acclimates to some gastric implantdevices, leading to an expansion of stomach volume and consequentreduction in the efficacy of the device.

Therefore, despite many advances in the design of intragastric obesitytreatment implants, there remains a need for improved implants that canbe implanted for longer periods than before or otherwise address certaindrawbacks of intragastric balloons and other such implants.

SUMMARY OF THE INVENTION

The present invention addresses the above-described problems byproviding passive intragastric apparatuses and methods for inducingsatiety and therefore treating obesity. Such passive devices do notautonomously change shape, but instead react within the stomach toinduce satiety. The devices may take up volume within the stomach, thusreducing the intake capacity. Additionally, the devices may contactareas within the stomach, such as the cardia surrounding the esophagealsphincter, to stimulate satiety-inducing nerves. Also, certain devicesslow gastric emptying by blocking or otherwise impeding flow through thepyloric sphincter. A number of devices combine two or more of thesesatiety-inducing features. Methods of implant are disclosed includingcompressing the devices within a delivery tube and transorally advancingthe devices through the esophagus to be deployed within the stomach.Removal of the devices occurs in the reverse.

One embodiment of a passive intragastric obesity treatment implantdisclosed herein comprises an inflatable body having a length sufficientto extend between the esophageal sphincter and the pyloric sphincterupon implant in the stomach, and a width sufficient to contact theinterior stomach walls upon contraction thereof. The body is rounded andslightly tapered so as to generally conform to the volume of an adultstomach cavity. The body further includes a plurality of or a series ofchambers fluidly connected so as to be capable of simultaneous inflationand deflation. Two chambers at a proximal end are separated by anannular recess that is positioned to open to the esophageal sphincter,wherein apertures in the annular recess open to a central flow channelthat extends from the annular recess to an inferior end of the body, andsome of the chambers surround the central flow channel. The implant isformed of a material which permits it to be compressed into asubstantially linear delivery configuration and that will resistdegradation over a period of at least six months within the stomach. Thecentral flow channel desirably has a star-shaped cross-section. Theimplant further may include a plurality of circumferential groovesextending around the body and between adjacent chambers, and radialpassages connecting the circumferential grooves to the central flowchannel. The chambers preferably gradually decrease in diameter from thesuperior to the inferior ends of the body. The body may have a roundedsuperior end that mimics the shape of the surrounding cardia and definesa proximal chamber therein.

Another passive intragastric obesity treatment implant comprises a foambody having a sufficient diameter so as to contact the interior stomachwalls upon contraction thereof, the foam body defining a centralthroughbore. A radially expandable and compressible stent lines thecentral throughbore, the stent having a tubular wall and struts across aproximal end to filter larger food particles. The implant is formed of amaterial which permits it to be compressed into a substantially lineardelivery configuration and that will resist degradation over a period ofat least six months within the stomach. The struts at the proximal endof the stent may be formed in a web of angled struts that extend inwardfrom the tubular wall and are joined together by a ring. The foam bodypreferably has a diameter of between about 10-20 cm.

A still further embodiment comprises a collapsible body defining a largebowl-shaped proximal end having a diameter sufficient to contact theinterior stomach walls upon contraction thereof. The proximal end has anartificial stoma opening through a bottom of the bowl shape. The bodyfurther includes a tapered hollow leg extending distally from theproximal end and an enlarged pyloric member on the distal end of theleg. The implant is formed of a material which permits it to becompressed into a substantially linear delivery configuration and thatwill resist degradation over a period of at least six months within thestomach. In a preferred embodiment, the body has an ear-horn shapenarrowing from the bowl-shaped proximal end along the leg to the pyloricmember. The leg includes a plurality of large apertures to permitingress of stomach juices to the interior of the leg. The body may beinflatable, and the stoma opening communicates with a flow-throughpassage that extends to the outside of the leg.

In a still further embodiment of a passive intragastric obesitytreatment implant, a hollow flexible tether has a lumen and a lengthsufficient to extend substantially the entire length of the stomachcavity from the pyloris to the esophageal/stomach junction and for adistance into the esophagus. A detention tray affixes to a proximalsection of the tether and has a size that impedes free passage of foodboluses entering the stomach from the esophagus. A series of inflatableballoons are affixed to the tether and are in fluid communication withthe lumen so as to be able to receive fluid from and be filled by fluidin the tether. The inflatable balloons include a pyloric balloon at adistal end of the tether having a size that will not pass through thepyloric sphincter. Further, the detention tray is positioned on thetether relative to the pyloric balloon so as to be located adjacent thecardia. The implant is made of a material that will resist degradationover a period of at least six months within the stomach. The detentiontray is preferably non-inflatable.

In one form, the detention tray is bowl-shaped with a concave proximalside. One of the inflatable balloons may be a positioning balloon sizedlarger than the others and positioned on the tether just distal to thedetention tray so that it contacts the surrounding cardia and centersthe tether and tray below the esophageal/stomach junction. Thepositioning balloon may have an arcuate outer section connected byspokes to a middle portion through which the tether passes, and theouter section may define a full circle. The pyloric balloon is desirablyshaped like a donut with a central through hole that permits passage ofchyme from the stomach to the pyloric sphincter. The inflatable balloonsfurther may include the pyloric balloon and a pair of sphericalintermediate balloons between the pyloric balloon and the detentiontray, the intermediate balloons maintaining a space between the tetherand the stomach wall. Finally, the implant may further include a fillvalve fitted to a proximal end of the tether, the fill valve havingstructure for mating with a fill tube nipple.

A further understanding of the nature and advantages of the inventionwill become apparent by reference to the remaining portions of thespecification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention will become appreciatedas the same become better understood with reference to thespecification, claims, and appended drawings wherein:

FIG. 1 illustrates an intragastric obesity device that substantiallyfills the stomach cavity and includes a flow-through channel therein,and

FIG. 2 is a longitudinal sectional view thereof illustrating fluid flowand peristaltic action with arrows;

FIG. 3 is a perspective of the device of FIG. 1 prior to implant;

FIG. 4 illustrates the device of FIG. 1 being removed from the stomachcavity;

FIG. 5 is a perspective view of an alternative stomach-fillingintragastric device having a foam body and a flow-through channel, andFIG. 5A is a longitudinal sectional view therethrough;

FIG. 6 is a perspective sectional view of the device of FIG. 5compressed within a delivery tube;

FIGS. 7A and 7B are expanded and contracted perspective views of a stentthat lines the flow-through channel of the device of FIG. 5;

FIG. 8 illustrates the device of FIG. 5 implanted within a stomachcavity, and FIG. 8A shows the shape of the device as it looks in thestomach cavity;

FIG. 9 shows a still further intragastric obesity treatment devicewithin the stomach having an upper bowl-shaped member with an artificialstoma, and FIG. 9A is a perspective view of the device;

FIG. 10 is an alternative device having an artificial stoma similar tothat in FIG. 9 implanted in the stomach, and FIG. 10A is a perspectiveview of the alternative device;

FIG. 11 shows an intragastric device including a series of tetheredelements within the stomach cavity that support a detention tray justbelow the esophageal sphincter;

FIGS. 12A-12C are isolated perspective and longitudinal sectional viewsof the device of FIG. 11;

FIG. 13 is a variation of the intragastric device of FIG. 11 having adetention tray below the esophagus, and with an enlarged positioningballoon:

FIGS. 14A-14B are isolated perspective and longitudinal sectional viewsof the device of FIG. 13;

FIG. 15 is still further variation of the intragastric device of FIG. 11with a detention tray below the esophagus, without a positioningballoon;

FIGS. 16A-16C are perspective and sectional views of an exemplary fillvalve and tube for use with the devices of FIGS. 11, 13 and 15;

FIGS. 17A-17B illustrate a still further intragastric implant in acontracted, delivery configuration;

FIGS. 18A-18B illustrate the intragastric implant of FIGS. 17A-17B in anexpanded, deployed configuration; and

FIGS. 19-21 illustrate intragastric devices that provide additionalstomach cavity stimulation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to a variety of different intragastricdevices that passively treat obesity by taking up space within thestomach or contact areas in and around the stomach to induce feelings ofsatiety. Furthermore, some devices described herein affect the rate ofstomach emptying. It should be understood that a number of the discloseddevices provide more than one of these passive aspects, and also thatany disclosed structure could be combined with another disclosedstructure unless physically impossible. As such, combinations of thepassive satiety-inducing features disclosed herein, even if notexplicitly stated, are contemplated. The term “passive” refers primarilyto a lack of any moving parts within the devices, but in general to theinert nature of the various devices. A passive device as defined herein,however, is not one that cannot affect change or stimulate the stomach,but rather one that may do so without any physical or chemical changesto its basic makeup.

FIG. 1 illustrates a first space-occupying device 160, but alsoillustrates the anatomy of the human stomach, which will be describedfirst. The major function of the stomach is to temporarily store foodand release it slowly into the duodenum. The esophagus extendingdownward from the mouth connects to the stomach via esophagealsphincter, which regulates flow food into the stomach cavity. The cardiasurrounds the superior opening of the stomach. The rounded portionsuperior to the body and adjacent the cardia is the fundus. Inferior tothe fundus is the large central portion of the stomach, called the body,that is lined with muscles that contract and relax repetitively to churnthe food therein. The stomach processes the food to a semi-solid“chyme,” which enables better contact with the mucous membrane of theintestines, thereby facilitating absorption of nutrients. In addition,the stomach is an important site of enzyme production.

Lower down in the stomach the antrum connects the body to the pyloris,which leads into the duodenum. Below the stomach, the duodenum leadsinto the upper part of the small intestine (not shown); the jejunummakes up about one-third of the small intestine. The region of thestomach that connects to the duodenum is the pylorus. The pyloruscommunicates with the duodenum of the small intestine via the pyloricsphincter (valve). This valve regulates the passage of chyme fromstomach to duodenum and it prevents backflow of chyme from duodenum tostomach.

Certain devices disclosed herein have flow-through channels and entirelyor almost-entirely fill the stomach. For instance, a stomach-in-stomachdevice 160 shown in FIGS. 1-3 includes an inflated soft body 161 thatconforms to the stomach and is generally convex. The device 160 has arounded superior end 162 that abuts the cardia, an annular recess 163adjacent thereto, and a gradually tapered and curved inferior portionthat conforms to the greater curvature of the stomach and terminates ina scalloped inferior end 164. The inflated body 161 seen in longitudinalsection within the stomach in FIG. 2 comprises a series of chambers 166fluidly connected so as to be capable of simultaneous inflation anddeflation. Besides a chamber 166 at the superior end 162, the body 161has three annular chambers 166 delimited by exterior circumferentialgrooves 167 and surrounding an inner generally longitudinal flow channel168. The three chambers 166 gradually decrease in diameter from thesuperior to the inferior end of the device 160. The flow channel 168extends from the annular recess 163 to the inferior end 164. A series ofapertures 169 open the inner channel 168 to the annular recess 163 nearthe superior end 162. Radial passages 170 extend between thecircumferential grooves 167 and the inner flow channel 168.

The device 160 is a saline-filled, soft, balloon-like structure shown ina pre-implant state in FIG. 3, which occupies and conforms to the entirestomach cavity. Once implanted and inflated, the device 160 assumes anarcuate path as it conforms to the stomach cavity, as in FIGS. 1 and 2.Due to the device size, available stomach volume is drastically reduced,so volume in which food mass may reside is far less than normal, and afeeling of satiety will occur sooner. As seen by the dashed-line arrowin FIG. 2, solid and liquid matter enters the annular recess 163 fromthe esophagus and passes inward to the inner channel 168 through theapertures 169. The inner flow channel 168 through the center connectsthe upper stomach to the lower, without obstruction of the pylorus andsubsequent delayed gastric emptying. The flow channel 168 has astar-like cross sectional shape such that peristaltic action of thestomach walls (inward arrows shown in FIG. 2) will transfer through tothe “sharp-walled” center channel, via hydraulic compression, and themechanical action upon the food will be improved as compared to a roundchannel. The central flow channel 168 acts as a smaller than normalstomach, so food intake cannot be as great as before device placement.

Although the primary food pathway is forced through the central flowchannel 168, some leakage around the device 160 will likely occur, whichis acceptable. The grooves 167 in the outside walls of the device 160help channel small solids and liquids to the smaller passages 170 thatradiate toward the larger, central channel 168. Smaller particles andsome liquids may pass directly into the pylorus through the scallopedatrium end 164 of the channel 168.

Additionally, the rounded superior end 162 of the device 160 pressesagainst cardia, thereby triggering release of satiety-inducing hormones,signaling the body to stop eating. The inflated device substantiallyfills the stomach cavity which maintains contact with the cardia.However, during food intake, the churning of the stomach walls willnaturally squeeze the device 160, such that the superior end 162 willpressurize and apply greater force to the cardia.

For device insertion, a lubricated, Teflon or similar material,thin-walled tube would be inserted down the esophagus, and partiallyinto the stomach, with the device compressed and pre-loaded inside thetube. Then the device would be maintained in its location by using afoot-ended wire or similar obturator, to bear on the compressed mass,and the delivery tube would be pulled back up the esophagus, andextracted through the mouth, leaving the device in place. While the tubeis removed, the resiliency of the material causes the device to “springopen” to its original/non-compressed shape. A valve (not shown) near thesuperior end may be provided for saline filling the body 161.

For device removal, as seen in FIG. 4, a lubricated tube 172 extendsdown through the esophageal sphincter and into proximity with thesuperior end 162. A wire or other device is used to deflate the body161, and the saline simply drains into the stomach. A grabber 174 passeddown the removal tube 172 then grabs the superior end of the body 161and pulls the device 160 into the tube. Because of the extremely softand flexible material used, such as certain fluoroelastomers, the device160 collapses easily into the tube 172.

Another device 180 that has a flow-through channel and almost-entirelyfills the stomach is shown in FIGS. 5-8. This device 180 occupies volumewithin the stomach; however, its main mode of action is the ability toexert pressure on the stomach walls in order to induce feelings offullness.

The device 180 consists of a collapsible tubular stent 182 surrounded bya generally annular foam body 184, and is seen pre-implant in FIGS. 5and 5A. The stent 182 provides a filtered pathway for food in thestomach to pass, which should limit the likelihood of gastroesophagealreflux disease (GERD). While providing some rigid structure to thedevice 180, the stent 182 is also compliant enough in the radialdirection to both facilitate implantation/explantation and accommodatestomach contractions.

The stent 182 is normally expanded, but can be compressed to a size thatallows for insertion and removal through a tube 185 passed through theesophagus, as seen in FIG. 6. A proximal end of the stent 182 isequipped with a ring 186 as seen in FIGS. 7A/7B that allows for either acustom or standard endoscopic tool to pull the stent into a sheath whichcollapses the structure. The stent 182 has a tubular wall 188 formed ofa latticework of interconnected struts that permit radially compressionand expansion. A web of angled struts 190 on the proximal end extendinward from the wall 188 and are joined together by the ring 186. Theangled struts 190 act as a filter for larger solid particles which helpsslow stomach emptying and may encourage a feeling of satiety if theproximal end of the device 180 is positioned close to the cardia. Incontrast to some other prior intragastric implants, the continually openpassageway through the device 180 helps prevent GERD. The stent 182 maybe made from materials including (but not limited to) rubbers,fluorosilicones, fluoroelastomers, thermoplastic elastomers,thermoplastics, thermosets, metals, or any combinations thereof.

The sponge like, foam body 184 (open or closed cell) surrounding thestent 182 fills the space across the stomach cavity, though does notextend the full length of the stomach, as seen in FIG. 8. In a preferredembodiment, the axial dimension of the foam body 184 is between about10-20 cm. The foam body 184 in its relaxed, uncompressed configurationas seen in FIG. 5 has a cylindrical outer surface 192, a cylindricalinner bore 194 that closely receives the stent 182, andoutwardly-projecting conical end surfaces 196. The foam body 184conforms to the shape of the stomach cavity when implanted, as seen inFIG. 8A. The foam material is durable enough to withstand the gastricenvironment and may be manufactured from materials including (but notlimited to) rubbers, fluorosilicones, fluoroelastomers, thermoplasticelastomers, or any combinations thereof. The foam body 184 acts as aspring within the stomach, continually placing pressure on the gastricwalls, independent of changes in the stomach shape and size. Because thestomach is an ever changing organ (in shape and size) both in the longterm (remodeling of the stomach after sustained changes in itsenvironment) and short term (stomach contractions, various bodypositions), it is difficult to create a single device which can maintainpressure on the gastric walls over a long period of time consistently.The diameter of the foam body 184 needs to be sufficiently large suchthat even in a large stomach, the foam exerts pressure on the gastricwalls. In an exemplary embodiment, the diameter of the foam body 184 isbetween about 10-20 cm.

The foam can be compressed and held in place during implantation andexplantation as in FIG. 6. Once implanted, the foam body 184 expands toconform to the approximate shape of the stomach. This pressure on thestomach walls encourages a feeling of fullness, without inhibitingnormal passage of food through the GI system. The absolute and relativesizes of the foam body 184 outer surface and inner bore diameters may beadjusted for different patients, with the bore diameter affecting therate of flow of solid and liquid matter therethrough. In one embodiment,the inner bore diameter of the foam body 184 is between about 2-4 cm.

A still further device 200 that provides a flow-through space is shownin FIGS. 9 and 9A, and comprises an implantable ear-horn-shaped body 202with a large bowl-shaped proximal end 204 tapering down in a distaldirection along a hollow leg 206 to a hollow spherical pyloric member208. The hollow leg 206 and pyloric member 208 are both interrupted by aplurality of apertures 210 that permit fluid communication between theinside and the outside of the hollow structures. Although hollow, thedevice 200 is not an inflated balloon. Rather, the material usedprovides sufficient stiffness to maintain the ear-horn shape as shown.

The device 200 is formed of a flexible material that allows it to becompressed and pre-loading into a delivery tube (not shown) foresophageal insertion into the stomach. Deployment of the device 200within the stomach cavity permits expansion of the device into theposition shown in FIG. 9, with the bowl-shaped proximal end 204 facingthe esophagus and the pyloric member 208 located within the pylorus.Device removal is accomplished using a standard grabber down a similartube which has been inserted down the esophagus, so the entire devicecan be pulled back into the tube and removed therewith.

The diameter and concavity of the bowl-shaped proximal end 204 allows itto contact the stomach cavity walls and intercept food and liquidentering through the esophageal sphincter. The proximal end 204 acts asa detention tray positioned just inside the stomach from the esophagealsphincter that presents a barrier to incoming food bound for thestomach, but which eventually overflows its contents into the stomach. Asmall drain hole 212 acts as an artificial stoma and permits a limitedamount of food and liquid past the proximal end 204 and into the cavityof the body 202. From there, gastric juices mixed with the foodparticles and begin the process of breaking them down into chyme. Thebody 202 is sufficiently flexible so that contractions of the stomachmuscles are transmitted therethrough. The diameter of the sphericalpyloric member 208 is sufficiently large that it cannot pass through thepyloric sphincter.

Because of the length of the body 202, and the curved shape of thedevice 200, the proximal end 204 contacts the walls around theesophageal junction, and against the cardia. In addition, the hollow leg206 serves as an anti-rotational feature to help hold the device inplace, and allow it to return to a normal position as shown, afterperistaltic waves in the stomach.

In a second embodiment seen in FIGS. 10 and 10A, an ear-horn-shapeddevice 200′ is configured the same as and works essentially like thedevice 200 of FIG. 9, except the device is a thinner-walled (hollow)balloon, intended to be saline-filled once inside the stomach. As such,like features will be given the same element numbers.

The second embodiment 200′ has a tube 214 that extends between the drainhole 212 and an opposite surface of the body 202, on the convex sidethereof. In this embodiment, food that passes through the drain hole 212does not enter the interior of the inflated body 202, but instead passesto the opposite side. The tube 214 tethers the bowl-shaped proximal end204 to the opposite surface of the balloon, so when saline-filled, theconcave bowl shape is retained. As in the first embodiment, the amountof food caught by and contained in the concave bowl 204 is far less thancan be held in an empty stomach. In both embodiments, when food entersthe bowl 204 it accumulates and applies pressure to the cardia, therebystimulating release of satiety-inducing hormones.

Deployment of the device 200′ within the stomach cavity is similar tothe earlier embodiment, but once deployed in the cavity the userinflates the body 202 through a fill valve 216 provided in the concaveproximal end 204. Removal of the inflated device 200′ is accomplished byinserting a tube down the esophagus, and clippers down the tube. Thedevice 200′ can then be clipped to evacuate the saline, and a standardgrabber can then be employed to pull the deflated balloon back into thetube for removal therewith. In the second embodiment, size adjustabilityis possible by removing or adding saline, whereas the first embodimentmay be supplied in a few different sizes.

Some food will normally leak out into the stomach, around the upper rimof the bowl 204, where it contacts the stomach lining. The remainingfood passes through the centrally-located small stoma 212, and into thestomach. The inflated embodiment 200′ is thought to have a morecompliant stoma than the non-inflated version 200, so food passage canbe somewhat easier.

FIGS. 11-16 illustrate additional intragastric devices that effectcardial stimulation to signal the brain to release the satiety-inducinghormones, which eventually slows eating, resulting in weight loss. Thesedevices feature a detention tray positioned just inside the stomach fromthe esophageal sphincter that presents a barrier to incoming food boundfor the stomach, but which eventually overflows its contents into thestomach. Much as prior art gastric bands restrict the free flow ofboluses of food into the stomach, the detention trays cause a temporarybackup of food at the esophageal/stomach junction, which inevitablycontacts the surrounding cardial walls and stimulates satiety.

As with earlier devices, those shown in FIGS. 11-16 are intended to betransorally placed, without the need for laparoscopic or other surgicalassist, and without the need for piercing of tissues to physicallyanchor the device. Further, these devices are intended to maintain theirposition without the need for stent-anchoring within the esophagus.Without some type of permanent positioning method, however, migration ofa stomach-implanted device can occur, with limited chance of the deviceever returning to its intended position. Instead, these devices achievetheir “anchoring” by loosely maintaining their position and “springingback” whenever moved. This is achieved by way of a hollow tether with aspringy/stiff consistency and a length spanning the length of thestomach from the pylorus to the cardia, so as to loosely hold the devicein position. The springy stiffness is due to either the use of a fairlystiff material for the tether itself, such a polypropylene, or via aco-extruded spring of various materials (e.g., Nitinol), molded withinthe lumen walls. The advantageous features of these devices will beclear after reading the detailed description below.

FIG. 11 shows an intragastric device 300 including a series of elementsspaced apart (“daisy-chained”) within the stomach cavity and connectedby a tether 302 that supports a detention tray 304 just below theesophageal sphincter. The device 300 has a length sufficient to extendsubstantially the entire length of the stomach cavity from the pyloristo the esophageal/stomach junction and for a distance into theesophagus. The device 300 includes a saline-filled proximal positioningballoon 306, a plurality of intermediate balloons 308, and a pyloricballoon 310, together which support/hold the tether 302 between thelesser and greater curvatures of the stomach. That is, the tether 302remains spaced from the stomach walls, and is curved to fit the anatomy,generally tracking the greater curvature of the stomach. The balloons306, 308, 310 can be provided in various configurations, as will be seenwith the proximal positioning balloon 306. In addition to helping holdthe device 300 in place as stomach movement occurs, the volume of theballoons, and the positioning balloon 306 in particular, are alsospace-occupying, similar to prior art spherical bioenteric balloons suchas the Orbera® System from Allergan Medical of Irvine, Calif. Forinstance, the aggregate volume of the balloons 306, 308, 310 may occupyapproximately the same volume (400 ml) as the aforementioned Orbera®System, which is proven sufficient to facilitate weight loss.

With reference again to FIG. 11, and also to FIGS. 12A-12C, thedetention tray 304 is a pliable, shallow conical or bowl-shapedstructure with a concave proximal side toward the esophagus. Theflexible tether 302 loosely holds the detention tray 304 in place at theproximal end thereof so as to be positioned just below the junction ofthe esophagus and stomach. That is, the tray 304 is positioned on thetether 302 relative to the pyloric balloon 310 so as to be locatedadjacent the cardia. The detention tray 304 is preferably notinflatable. The tether 302 projects both distally towards its distaltermination at the pyloric balloon 310 and proximally from the tray 304.The proximal end of the tether 304 extends into the lower portion of theesophagus and preferably features a fill valve 312 at its proximalterminus. As the stomach and esophagus undergo normal peristalticactions, it is expected that the entire device 300 will migrate aroundto some degree, but most of the time the device is anticipated to returnto its normal position as shown, with the tray loosely “sealed” in placeagainst the cardia adjacent the gastro-esophageal junction.

The fill valve 312 at the proximal terminus of the tether 302 allowssaline to be added though a detachable fill tube (not shown) inserteddown the esophagus, and includes a self-closing slit to hold the salineinside the device 300. Details of an exemplary fill valve 312 will beprovided below with reference to FIGS. 16A-16C. The length of the tether302 runs through the tray 304 and though the hollow balloons 306 and 308to terminate at the pyloric balloon 310. The distal end of the tether302 is attached, open-ended inside the annular- or donut-shaped pyloricballoon 310 for filling it with saline. Small side holes (not shown)through the side wall of the tether 302 within the proximal positioningballoon 306 and the intermediate balloons 308 provide for their fillingalso. The entire series of balloons 306, 308, 310 can therefore befilled after placement within the stomach via the proximal fill valve312. The proximal end of the tether 302 extending into the esophagus isalso intended to help maintain the centered position of the detentiontray 304 against the cardia, pressed upwards from the pylorus. Duringstomach movement the proximal end of the tether 302 may in fact traveldownward, loosening the tray intermittently, but the tether shall be ofsufficient length to prevent its migration completely out of theesophagus at any time. In one embodiment, the total length of the device300 from the fill valve 312 to the pyloric balloon 310 is between about35-40 cm when the tether 302 is measured in a straight line.

Now with particular reference to FIGS. 12A-12C, characteristics of theexemplary balloons 306, 308, 310 will be described. First of all, theintermediate balloons 308 are desirably spherical and identical, butthey may also be provided with exterior features (e.g. bumps) such asdescribed below, and they may be dissimilar. The twin sphericalintermediate balloons 308 are intended to cushion the tether 302 fromdirectly/sharply touching the greater curvature of the stomach.

The largest balloon, the proximal positioning balloon 306, features anarcuate, generally semi-circular outer section 320 connected at eitherend to radial spoke sections 322 that meet in the middle along an axisof the structure through which the tether 302 passes. A shorter radialspoke section 324 extends between the outer section 320 and theconvergence of the larger spoke sections 322 in the middle of theballoon 320, and generally extends along a plane that bisects theballoon into two symmetric halves. Two apertures 325 formed between theouter section 320 and the spoke sections 322, 324 permit passage of foodtherethrough such that the positioning balloon 306 does not present asolid barrier to churning movement of food within the stomach. As seenbest in FIG. 11, the positioning balloon 306 as viewed from the side hasa gradual taper such that its axial thickness, or height, is greatertoward the middle of the balloon where the tether 302 passes than at theouter section 320.

Finally, the pyloric balloon 310 has a generally spherical outer shapewith a lumen 326 extending axially through the middle to create a donutshape. The lumen 326 through the center of the pyloric balloon permitsnormal egress of food from the stomach into the duodenum. The inflatedpyloric balloon 310 cushions against the pylorus without making a tightseal, but intermittently “sealing” nonetheless. This tends to delaygastric emptying. As seen best in FIG. 12B, the tether 302 terminateswithin one side of the axi-symmetric balloon 310 and a cavity formedtherein extends around 360° so the balloon may be evenly filled via thetether.

FIG. 13 is a variation of an intragastric device 330 similar to thatshown in FIG. 11. The device 330 includes an elongated curved tether 332that positions a detention tray 334 below the esophagus, and includes anenlarged positioning balloon 336, a pair of intermediate balloons 338,and a pyloric balloon 340. FIGS. 14A-14B show details of the device 330of FIG. 13. In particular, the enlarged positioning balloon 336 featuresa complete outer circular section 342 having a pair of diametricperpendicular spokes 344 defining food passages therebetween andextending across a middle portion through which the tether 332 passes.The complete circular section 342 of the positioning balloon 336 mayprovide improved “anchoring” of the device 330 within the stomach. Inother respects the intragastric device 330 is the same as theabove-described intragastric device 300.

FIG. 15 is still further variation of an intragastric device 350 likethat of FIG. 11, with a detention tray 352 below the esophagus on atether 354, but without a proximal positioning balloon. The device 350still has a pair of intermediate balloons 356 and a distal pyloricballoon 358.

An exemplary fill valve 312 for use with the device 300 of FIG. 11 (andalso the devices of FIGS. 13 and 15) is shown in FIGS. 16A-16C. Thevalve 312 includes an enlarged proximal end 360 which steps down indiameter to a distal insert section 362 that fits tightly within a lumen364 of the hollow tether 302. A generally inwardly-conical lead-in mouth370 opens into a retention chamber 372 within the proximal end 360. Atthe bottom of the retention chamber 372, a slit passage 374 extendsthrough to the distal end of the insert section 362. A fill tube (notshown) has a barbed nipple or other feature that may be forced throughthe lead-in mouth 370 and captured within the retention chamber 372.Saline under pressure can then be forced through the slit passage 374and into the lumen 364 of the tether 302. After removal of the filltube, the slit passage 374 closes up, thus sealing the saline within thedevice 300 and its daisy-chained balloons.

FIGS. 17A-17B illustrate a still further flow-through intragastricimplant 400 in a contracted, delivery configuration, while FIGS. 18A-18Billustrate the implant 400 in an expanded, deployed configuration. Theimplant 400 is in the shape of an inflated tube, with an outer tubularwall 402 joined to an inner tubular wall 404 at circular ends 406. Aflow-through lumen 408 extends from end to end. The implant 400 may bedelivered in a relatively small tube as seen in FIGS. 17A-17B and theninflated within the stomach to the larger tubular shape of FIGS.18A-18B. A fill valve (not shown may be provided in the outer wall 402or at one of the ends 406. The inflated shape in FIG. 18A is relativelyshort axially and wide in diameter so that it may rotate within thestomach. In a preferred embodiment, the axial dimension is between about5-10 cm, while the outer diameter is between about 4-8 cm, with the lowbound of each range coinciding with the low bound of the other range,and vice versa. Uneven exterior surface features such as described belowmay be added to further provide stimulation. Additionally, the volume ofthe implant 400 may occupy approximately the same volume (400 ml) as theaforementioned Orbera® System, which is proven sufficient to facilitateweight loss

While not shown, the outer surface of the intragastric devices disclosedherein may further include additional uneven surface features such assmall rounded bumps or protrusions, quill-like extensions, dimples orrecesses, and the like. These features, upon contact with the innerstomach wall of the patient may further trigger hormone release orotherwise aid the patient in feeling full. Such features may beparticularly effective for those embodiments which stimulate the cardia.The examples in FIGS. 19-21 may be applied to any of the various devicesand surfaces disclosed herein.

For instance, FIG. 19 illustrates a spherical intragastric device 510having numerous external protrusions or bumps 512 projecting outwardtherefrom. These bumps 512 separately contact the inner walls of thestomach, potentially increasing the stimulation to the surroundingsatiety-sensing nerves. As shown, a plurality of bumps 512 may beequally spaced apart on the outer surface and interspersed with flatportions. In one embodiment, the bumps 512 may be of equal heights anddiameters, or they may be configured to have different heights and/ordiameters. For example, having bumps 512 with different heights and/ordiameters may be advantageous for preventing the stomach from adjustingto the bumps. The bumps 512 separately contact the inner walls of thestomach, potentially increasing the stimulation to the surroundingsatiety-sensing nerves.

Another example of exterior stimulation features is seen in FIG. 20,where an intragastric device 520 formed as a sphere features a multitudeof small flagella or quill-like extensions 522 extending outwardtherefrom. As shown, a plurality of extensions 522 may be equally spacedapart. In one embodiment, the extensions 522 may be of equal heights anddiameters, or they may be configured to have different heights and/ordiameters. In one embodiment, the extensions 522 may be extremelyflexible and may bend when a pressure is exerted on them from the innerstomach wall of the patient. Alternatively, the extensions 522 may bestiffer and might not bend as much when a pressure is exerted on themfrom the inner stomach wall of the patient. In another embodiment, someof the extensions 522 may have a first flexibility while some of theextensions may have a second flexibility.

FIG. 21 illustrates another example of uneven surface features on anintragastric device 550. As shown, the intragastric device 550 is asubstantially spherical object with recesses or dimples 555 extendinginward from the surface of the intragastric device 550. In oneembodiment, the intragastric device 550 may be considered to have asurface comprised of recesses 555 and flat portions 560. As shown, aplurality of recesses 555 may be equally spaced apart on the outersurface. As shown, recesses 555 do not contact each other, and may be ofequal heights and diameters. In addition to being depressed, therecesses 555 may employ a thinner wall. For example, if the flatportions 560 have a wall thickness of 20 millimeters, the recesses 555may have a wall thickness of 10 millimeters. With a thinner wall, therecesses 555 may be more susceptible to larger strains. The intragastricdevice 550 is effectively triggered in the patient's stomach by stomachcontractions. These stomach contractions increase the pressure in theintragastric device 550. If one recess 555 is not in contact with thestomach wall, it will deform outward until it comes into contact withthe stomach wall.

It should be noted that the embodiments shown in FIGS. 19-21 rotatefreely within the stomach, and that the bumps 512, quill-like extensions522, or recesses 555 may be provided in a non-uniform distribution so asto take advantage of the benefits of the rotational variation describedabove. That is, a regular array of such exterior features may stimulatethe stomach wall more than a smooth surface, but also providing anon-uniform distribution will create different sensations on aconstantly changing basis.

It should also be stated that any of the embodiments described hereinmay utilize materials that improve the efficacy of the device. Forexample, a number of elastomeric materials may be used including, butnot limited to, rubbers, fluorosilicones, fluoroelastomers,thermoplastic elastomers, or any combinations thereof. The materials aredesirably selected so as to increase the durability of the device andfacilitate implantation of at least six months, and preferably more than1 year.

Material selection may also improve the safety of the device. Some ofthe materials suggested herein, for example, may allow for a thinnerwall thickness and have a lower coefficient of friction than the currentdevice which may aid in the natural passage of the balloon through theGI tract should the device spontaneously deflate.

The implantable devices described herein will be subjected to clinicaltesting in humans. The devices are intended to treat obesity, which isvariously defined by different medical authorities. In general, theterms “overweight” and “obese” are labels for ranges of weight that aregreater than what is generally considered healthy for a given height.The terms also identify ranges of weight that have been shown toincrease the likelihood of certain diseases and other health problems.Applicants propose implanting the devices as described herein into aclinical survey group of obese patients in order to monitor weight loss.

The clinical studies will utilize the devices described above inconjunction with the following parameters.

Materials:

a. Silicone materials used include 3206 silicone for any shells,inflatable structures, or otherwise flexible hollow structures. Any fillvalves will be made from 4850 silicone with 6% BaSo₄. Tubular structuresor other flexible conduits will be made from silicone rubber as definedby the Food and Drug Administration (FDA) in the Code of FederalRegulations (CFR) Title 21 Section 177.2600.

Purposes:

a. the devices are for human implant,

b. the devices are intended to occupy gastric space while also applyingintermittent pressure to various and continually changing areas of thestomach;

c. the devices are intended to stimulate feelings of satiety, therebyfunctioning as a treatment for obesity.

General Implant Procedures:

a. The device is intended to be implanted transorally via endoscope intothe corpus of the stomach.

b. Implantation of the medical devices will occur via endoscopy.

c. Nasal/Respiratory administration of oxygen and isoflurane to be usedduring surgical procedures to maintain anesthesia as necessary.

One exemplary implant procedure is listed below.

a. Perform preliminary endoscopy on the patient to examine the GI tractand determine if there are any anatomical anomalies which may affect theprocedure and/or outcome of the study.

b. Insert and introducer into the over-tube.

c. Insert a gastroscope through the introducer inlet until the flexibleportion of the gastroscope is fully exited the distal end of theintroducer.

d. Leading under endoscopic vision, gently navigate the gastroscope,followed by the introducer/over-tube, into the stomach.

e. Remove gastroscope and introducer while keeping the over-tube inplace.

f. OPTIONAL: Place the insufflation cap on the over-tubes inlet, insertthe gastroscope, and navigate back to the stomach cavity.

g. OPTIONAL: Insufflate the stomach with air/inert gas to providegreater endoscopic visual working volume.

h. Collapse the gastric implant and insert the lubricated implant intothe over-tube, with inflation catheter following if required.

i. Under endoscopic vision, push the gastric implant down the over-tubewith gastroscope until visual confirmation of deployment of the deviceinto the stomach can be determined.

j. Remove the guide-wire from the inflation catheter is used.

k. If inflated: Inflate the implant using a standard BioEntericsIntragastric Balloon System (“BIB System”) Fill kit.

l. Using 50-60 cc increments, inflate the volume to the desired fillvolume.

m. Remove the inflation catheter via over-tube.

n. Inspect the gastric implant under endoscopic vision for valveleakage, and any other potential anomalies. Record all observations.

o. Remove the gastroscope from over-tube.

p. Remove the over-tube from the patient.

End Point Criteria:

Weight Loss

Comprehensive Metabolic Panel (CMP)

HbA1C

Lipid Panel

Tissue Samples/Response

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, reaction conditions,and so forth used in the specification and claims are to be understoodas being modified in all instances by the term “about.” Accordingly,unless indicated to the contrary, the numerical parameters set forth inthe specification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained. At the veryleast, and not as an attempt to limit the application of the doctrine ofequivalents to the scope of the claims, each numerical parameter shouldat least be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the disclosure are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

The terms “a,” “an,” “the” and similar referents used in the context ofdescribing the invention (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.Recitation of ranges of values herein is merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention otherwise claimed. No languagein the specification should be construed as indicating any non-claimedelement essential to the practice of the invention.

Groupings of alternative elements or embodiments of the inventiondisclosed herein are not to be construed as limitations. Each groupmember may be referred to and claimed individually or in any combinationwith other members of the group or other elements found herein. It isanticipated that one or more members of a group may be included in, ordeleted from, a group for reasons of convenience and/or patentability.When any such inclusion or deletion occurs, the specification is deemedto contain the group as modified thus fulfilling the written descriptionof all Markush groups used in the appended claims.

Certain embodiments are described herein, including the best mode knownto the inventors for carrying out the invention. Of course, variationson these described embodiments will become apparent to those of ordinaryskill in the art upon reading the foregoing description. The inventorexpects skilled artisans to employ such variations as appropriate, andthe inventors intend for the invention to be practiced otherwise thanspecifically described herein. Accordingly, this invention includes allmodifications and equivalents of the subject matter recited in theclaims appended hereto as permitted by applicable law. Moreover, anycombination of the above-described elements in all possible variationsthereof is encompassed by the invention unless otherwise indicatedherein or otherwise clearly contradicted by context.

Furthermore, references may have been made to patents and printedpublications in this specification. Each of the above-cited referencesand printed publications are individually incorporated herein byreference in their entirety.

Specific embodiments disclosed herein may be further limited in theclaims using “consisting of” or “consisting essentially of” language.When used in the claims, whether as filed or added per amendment, thetransition term “consisting of” excludes any element, step, oringredient not specified in the claims. The transition term “consistingessentially of” limits the scope of a claim to the specified materialsor steps and those that do not materially affect the basic and novelcharacteristic(s). Embodiments of the invention so claimed areinherently or expressly described and enabled herein.

In closing, it is to be understood that the embodiments of the inventiondisclosed herein are illustrative of the principles of the presentinvention. Other modifications that may be employed are within the scopeof the invention. Thus, by way of example, but not of limitation,alternative configurations of the present invention may be utilized inaccordance with the teachings herein. Accordingly, the present inventionis not limited to that precisely as shown and described.

What is claimed is:
 1. A passive intragastric obesity treatment implantfor placement within a stomach, comprising: a foam body, forming aportion of an outer surface of the implant, having a sufficient outerdiameter so as to contact interior walls of the stomach upon contractionthereof, the foam body having an inner diameter defining a centralthroughbore of the foam body: a radially expandable and compressiblestent lining the central throughbore, the stent having a tubular walland struts across a proximal end to filter larger food particles, theimplant being formed of a material which permits it to be compressedinto a substantially linear delivery configuration and that will resistdegradation over a period of at least six months within the stomach,wherein the central throughbore has a diameter between about 2-4 cm andthe foam body has a thickness, measured between the outer diameter andthe inner diameter, between about 6-18 cm.
 2. The implant of claim 1,wherein the foam body has an outer diameter of between about 10-20 cm.3. The implant of claim 1, wherein the struts extend inwardly andproximally at an angle from respective bases at the tubular wall torespective proximal ends at the proximal end of the stent, and furthercomprising a ring at the proximal end of the stent joining the proximalends of the struts together, wherein the bases of the struts areconnected to the tubular wall but are not connected directly together bya ring.
 4. A passive intragastric obesity treatment implant forplacement within the stomach, the implant consisting of: a radiallyexpandable and collapsible tubular stent, the stent having a latticeworktubular wall and interconnected struts that cross a proximal end of thestent and that permit radial compression and expansion and providing afiltered pathway that slows passage of food therethrough wherein thestruts extend inwardly and proximally at an angle from respective basesat the tubular wall to respective proximal ends at the proximal end ofthe stent; and an annular foam body, forming a portion an outer surfaceof the implant, surrounding the stent and having a radial size to fill aspace across the stomach, and an axial size that does not extend a fulllength of the stomach, the implant being formed of materials whichpermit it to be compressed into a substantially linear deliveryconfiguration and that will resist degradation over a period of at leastsix months within the stomach wherein the foam body has a thickness thatis greater than or equal to a diameter of the central throughbore. 5.The implant of claim 4, wherein the foam body has an outer diameter ofbetween about 10-20 cm.
 6. The implant of claim 5, wherein the foam bodydefines an inner bore in which the stent is received, the inner borehaving a diameter between about 2-4 cm.
 7. The implant of claim 6,wherein the foam body is annular and has a thickness between 6-18 cm. 8.The implant of claim 4, wherein the foam body has an axial dimension ofbetween about 10-20 cm.
 9. The implant of claim 4, wherein the stent ismade from one of a rubber, fluorosilicone, fluoroelastomer,thermoplastic elastomer, thermoplastic, thermoset, metal, or anycombination of the foregoing.
 10. The implant of claim 4, wherein thefoam body is an open cell foam.
 11. The implant of claim 4, wherein thefoam body is a closed cell foam.
 12. The implant of claim 4, wherein thefoam body in a relaxed, uncompressed configuration has a cylindricalouter surface, and a cylindrical inner bore that closely receives thestent.
 13. The implant of claim 12, wherein the foam body hasoutwardly-projecting conical end surfaces.
 14. The implant of claim 4,wherein the foam body is made from one of a rubber, fluorosilicone,fluoroelastomer, thermoplastic elastomer, or any combination of theforegoing.
 15. The implant of claim 4, wherein the foam body defines aninner bore in which the stent is received, the inner bore having adiameter between about 2-4 cm.